Rain covers in modern neon yellow and blue ensure the contents of your rucksack are still dry after a day out in bad weather. Excellent rain protection thanks to PU coating and taped seams. The luminous colours are for additional safety on roads or in an emergency.

It should be fine -- this rain cover is intended for Deuter packs ranging from 45L to 90L, which is a pretty broad range. I think even with the pockets full of stuff and the pack crammed to its max capacity, you'll be able to use this happily.